A polymer comprising mainly repeating units (1) and/or repeating units (2), containing optionally terminal groups (3) and/or repeating units (4), and having a reduced viscosity [ eta sp/c] of 0.2 to 10.0 dl/g as measured in a 0.5 g/dl solution thereof in methylene chloride at 20 DEG C; a resin coating fluid containing the polymer, a charge-transfer substance and a solvent; and an electrophotographic photoreceptor containing the polymer as a binder resin in a photosensitive layer, wherein Rf represents a group that is composed of at least carbon and fluorine atoms and bonded directly to the two oxygen atoms of the carbonate linkage in the general formula (1) without any intervening arylene group; and Rf represents a group that is composed of at least carbon and fluorine atoms and bonded directly to one of the oxygen atoms of the carbonate linkage in the general formula (3) without any intervening arylene group.